Sionell, born in 708, was the oldest child of Walvis and Feylin, and a little hellion. Stubborn to a fault, she had the lucky place of being the thorn in young Pol's side. She wanted to follow him everywhere. He wanted nothing to do with a little 'baby' as he called her. Sionell would stomp her little foot and say she wasn't a baby. As all people do, Sionell grew up. She grew into a strong and hot-tempered young woman, and very opinionated to boot, but she was also kindhearted and caring. She had always been half in love with Pol and as she got older that love grew too. Pol, for his part, viewed her more as a kid sister than anything else. Another young man noticed the beautiful woman she had become, however. His name was Tallain of Tiglath. He was a shy and quite young man, but he was a strong one too. He came out of his shell in part due to his relationship with Sionell and she matured with grace due to his. The two found love and were eventually married, though Sionell never forgot her first love, Pol. Sionell and Tallain had three children together, Antalya, Jahnev, Meig.

Tigalth was one of the Keeps attacked during the Vellanti invasion. Tallain had some warning of their impending arrival, and though he asked Sionell to flee the castle with the Tiglathis, she refused, wanting to fight beside her husband. To protect his wife, Tallain drugged her and sent her, unconscious, to Feruche with a number of Tigathis. Tallain and his men were able to fend off the invaders long enough for Sionell and others to get away, but he and the brave defenders of Tiglath had fallen.

Sionell was a great asset during the war. She helped plan against further attacks, and took part in Sioned's scheme to drug the Vellanti soldiers - she did not know the drug was actually poison; however, and wasn't terribly pleased when she discovered it. Many times during the war she would speak to Pol, trying to keep him focused and on track. He needed her to yell him into actions on a few occasions. In the end, Pol and his forces won the war and drove the Vellant'im from the Continent. Pol also finally saw Sionell as a strong woman and not the little girl who had followed him around, pestering him. Shortly before Meiglan's death at the hands of the Vellant'im, she and Pol were romantically involved for a brief encounter. It was too little too late, though. Sionell, while she still cared deeply for him and perhaps even loved him, couldn't help but remember Tallain's selfless bravery and unfaltering love. Instead of staying with Pol, Sionell accepted the Regency of Cunaxa.